After a secretly-recorded videotape was released on Sept. 17, showing Mitt Romney making unflattering comments about the “47 percent” of Americans whom he said had become dependent on government benefits, I suggested on Twitter that the political impact of the comments could easily be overstated.

“Ninety percent of ‘game-changing’ gaffes are less important in retrospect than they seem in the moment,” I wrote.

But was this one of the exceptional cases? A week and a half has passed since Mr. Romney’s remarks became known to the public — meaning that there’s been enough time to evaluate their effect on the polls.There’s a case to be made that they did damage Mr. Romney’s standing some.

In the chart below, I’ve tracked the progress of the national popular vote in the FiveThirtyEight “now-cast” over the past five weeks. The “now-cast” reflects our best estimate of what would happen in an election held today, based on a combination of recent national and state polls.

...By Sept. 17, the date when the video of Mr. Romney’s remarks was released and received widespread attention, the momentum from Mr. Obama’s convention appeared to have stalled (although not necessarily reversed itself). Mr. Obama led in the popular vote by 4.1 percentage points on that date, according to the “now-cast.”

Since then, however, Mr. Obama has gained further ground in the polls. As of Thursday, he led in the popular vote by 5.7 percentage points in the “now-cast,” a gain of 1.6 percentage points since Mr. Romney’s remarks became known to the public.

It’s hard to tell whether this recent gain for Mr. Obama reflects the effect of the “47 percent” comments specifically. But the most typical pattern after a party convention is that a candidate who gains ground in the polls cedes at least some of it back.